“The weather used to be good, but the climate has changed over time,” says Munir, who works at a salon in Colaba. A March 2025 report brought out by Respirer Living Sciences confirms Munir’s experience and observations. Colaba has become an urban heat island (UHI).
Mumbai faced a particularly harsh summer this year. While the monsoon arrived early and brought respite from the intense heat, the UHI effect in certain pockets remains an ongoing challenge. It has led to the creation of microclimate zones in the island city. As a result, some parts of Mumbai see a considerably higher temperature than the surrounding areas.
The Mumbai Climate Action Plan has also analysed data to identify urban heat islands. While the UHI effect in itself is significant, when taken in conjunction with inadequate heat-related policies, the problem is magnified.
Read more: Keeping it cool: How Mumbai’s building rules must address heat stress
Factors such as age, gender, occupation, and socio-economic conditions heavily influence vulnerability to heat. Moreover, heat can exacerbate the hazards posed by underlying health issues such as cardiovascular disease, diabetes and mental health disorders. The World Health Organization, recognising the impact of heat on health, has brought out a framework to build climate-resilient health systems. Besides health, extreme heat also impacts livelihoods, especially for people working outdoors or with no access to air-conditioning.
To address these urgent issues, we need robust policies to be effectively implemented. “There is no policy that connects the dots between health impacts and heat stress,” says Sarita Fernandes, convener of the Heatwave Action Coalition (India).
Citizen Matters explored the fallout of the UHI effect in a video story, with a focus on Colaba. This video looks at the experiences of people living and working in Colaba as well as the gaps in policies which address urban heat.
Also read:
- Climate laws must enforce heat mitigation measures: Professor Vidhya Venugopal
- Can blue green infrastructure fix Mumbai’s floods and heat waves?